The present invention relates to a novel and useful apparatus for tuning an acoustic drum. Drums are comprised of several simple components including a drum head, most commonly made of a plastic material called Mylar, which include a rigid rim, generally made of a metallic material. The drum shell; most often made of layers of laminated wood, lexan plastic, aluminum, fiberglass or carbon fiber and formed to a cylindrical shape with two open ends. The drum head is stretched over the drum shell by means of a multiplicity of evenly spaced bolts inserted through holes around the diameter of a ring often made of stamped steel, die cast zinc, aluminum or wood known as the hoop. These bolts are threaded into what are commonly referred to as lugs which are generally attached to the drum shell by bolts inserted though holes drilled into the drum shell. Evenly adjusting the tension of these individual bolts causes the drum head to be tuned either higher or lower in pitch.
The current and most commonly used method for tuning drums is a best depicted by U.S. Design Pat. No. Fuji D350,362. Referred to as the drum hoop, it has a plurality of evenly spaced holes in it for bolts to be inserted through in order to exert tension on the drum head, it's overall shape designed to fit over the drum head. U.S. Design Pat. No. D339,818 is an example of lugs which are fastened to the drum shell and serve as anchors for the bolts inserted through the drum hoop previously mentioned. The earliest designs of this current hoop are U.S. Pat. No. 794,658 dated Jul. 11, 1905 show a combination of L cross section or “angle iron” rings, one with the vertical with surface facing upward, the other overlapping the horizontal surface and its vertical surface facing downward with holes about the horizontal flange for clamping down the drumhead. U.S. Pat. No. 899,488 dated Sep. 22, 1908 having an inverted U shaped Cross Section with evenly spaced holes around its perimeter. The first early modern design is U.S. Pat. No. 1,609,940 dated Dec. 7, 1926 appears to be the one piece conterhoop having an “L” cross section with the horizontal flange having evenly spaced holes for clamping the drum head to the open end of the drum shell. U.S. Pat. No. 6,166,311 was designed as an improvement to the drum hoop, an inward facing horizontal annular surface at the top of the hoop provides protection to the bearing edge of the drum shell, and a byproduct is increased rigidity of the drum hoop.
To evenly apply tension to the drum head to set the correct pitch takes a great amount of time and skill, often being time consuming and frustrating. To deal with this, systems for tuning drums have been proposed simplify this common task. U.S. Pat. No. 6,043,419 is comprised of a large counter hoop with a plurality of inward facing slides angled to act as ramps which ride on rollers or matching opposing slides fastened to the drum shell. It is tuned by rotating the drum clockwise or counterclockwise using a rack and pinion activation system. This tuning system employs individual adjusting screws to be able to fine tune the drum to make up for irregularities in drum heads. U.S. Pat. No. 5,739,448 is comprised of an inverted J-shaped counterhoop, which engages an externally threaded, outwardly facing tuning rim surface on a tuning collar that is secured to the drum shell. Clockwise or counterclockwise rotation of the counterhoop is accomplished by a pair of gears, one for gross tuning, and one for fine tuning.
U.S. Pat. No. 6,043,419 is the original inventor's improvement over U.S. Pat. No. 6,043,419 which utilizes a V Clamping mechanism which engages a counterhoop which has downwardly and outwardly extending flange which bears on the drum head and a flanged shell hoop fastened to the drum shell, its flange portion inclined upwards and outwards. The V clamp ring which surrounds the drum shell and engages both the outwardly extending portions of the counterhoop and the shell hoop contains a breach, tightening a bolt connecting the breached area draws the two hoops together and applies tension to the drum head. Contraction of the V clamp ring exerts an inward compression force which draws the counter-hoop towards the shell hoop which tensions the drum head against the drum shell, thereby raising the pitch of the drum.
The present applicant's solution to simplifying tuning was addressed in U.S. Pat. No. 7,138,574. To provide a better understanding of the improvements made to the present invention, a detailed summary of U.S. Pat. No. 7,138,574 is presented below;
U.S. Pat. No. 7,138,574 describes a drum tuning system comprised of a two main components. The first component being a spiral cam ring which is fastened to the cylindrical drum shell and functions as the cam. The spiral cam ring encircles the vertical surface of the drum shell and is fastened in the vicinity near the opened end of the drum shell. The spiral cam ring utilizes a spiraling groove or track around its outside diameter starting at the top of the spiral cam ring spiraling down and exiting at the bottom of the ring forming a shallow angular pitch or ramp.
The second component is made up of a pair of cylindrical rings or annular members. The first ring being a smaller inner counterhoop having both vertical and horizontal surfaces, its vertical surface extending upward, its horizontal surface extending outward on the bottom radially, forming an L cross section.
The second ring being a larger outer rotating actuator ring encompasses the spiral cam ring and has a vertical surface that runs parallel to the spiral groove or track at its outside diameter, and an inward facing horizontal surface atop the vertical surface forming an inverted L cross section. The inward facing horizontal surface of the rotating actuator ring (top) overlaps the inner counterhoops horizontal surface (bottom) and smaller inside diameter of the upward extending vertical surface forming an interlocking L and inverted L cross section. The overlapping horizontal surfaces of the inner counterhoop and the outer rotating actuator ring are separated by bearings or rollers, a ring style retainer is employed to keep the inner counterhoop and outer rotating actuator ring together and assembled to retain the bearings or rollers. These rollers dramatically reduce friction created by the downward force when turning the rotating actuator ring against the stationary inner counterhoop.
The rotating actuator ring engages the track or groove of the spiral cam ring by means of inward facing projections, rollers or wheels mounted on its inside diameter at its vertical surface at opposing intervals and varied heights radially matching the angular ramp on the groove or track of the spiral cam ring keeping them perpendicular to one another. Turning the rotating actuator ring clockwise or counterclockwise has a camming effect which increases or decreases the downward force on the inner counterhoop which bears down on the outer rim of the drum head when fitted over the open end of the drum shell, altering the pitch of the drum thereby tuning it.
This invention mainly focused on the mechanical aspects of altering the tension of a drum head by the most efficient and accurate means possible. Saving the musician time changing drum heads and tuning the drum was the primary focus; its secondary focus was its adaptability to be retrofitted onto existing drums.